Jonathan Gillette, better known as why the lucky stiff (often abbreviated to Why or _why), was until 2009 a prolific writer, cartoonist, artist, and computer programmer notable for his work with the Ruby programming language. He was known as "one of the most unusual, and beloved, computer programmers" in the world before he abruptly disappeared from public view.[1] Along with Yukihiro Matsumoto and David Heinemeier Hansson, he was seen as a key figure in the Ruby community.

_why was the keynote speaker at RailsConf in 2006. He also had a speaking session titled "A Starry Afternoon, a Sinking Symphony, and the Polo Champ Who Gave It All Up for No Reason Whatsoever" at the 2005 O'Reilly Open Source Convention held in Portland, Oregon.It explored how to teach programming and make it more appealing toadolescents.

On 19 August 2009, his online presence was drastically truncated; his accounts on Twitter and GitHub were shut down, along with many of his personally maintained sites.His projects have since been collected and centralized on the whymirror GitHub account.

On 5 January 2013, _why's site was found to be back online. The front page has been updated to point to documents readable by a printer.